package Test001;

public class Number {
    public Number() {
    }

    public static double add(double a, double b){
    return a+b;
}
public static double subtract(double a,double b){
    return a-b;
}
public static double multiply(double a,double b){
    return a*b;
}
public static double divide(double a,double b){
    if(b==0){
        System.out.println("错误，除数不能为0");
    }
        return a/b;
}
}
